Defines axial tensile testing of metallic materials at low and cryogenic temperatures (typically between about +10 °C and −196 °C, liquid-nitrogen level) to assess mechanical limits and brittle-to-ductile behaviour in cold service.
ISO 6892-3
Revision: 2015
Material testing
Metallic materials — Tensile testing — Method of test at low temperature
Defines axial tensile testing of metallic materials at low and cryogenic temperatures (typically between about +10 °C and −196 °C, liquid-nitrogen level) to assess mechanical limits and brittle-to-ductile behaviour in cold service.
Test method
A specimen is cooled uniformly, gripped, and pulled while force and extension are recorded; temperature must remain stable through the gauge section. Strain measurement requires extensometers and grips that retain accuracy despite contraction and frost effects.
Specimen requirements
Specimen types align with ISO 6892-1 where applicable; conditioning time, transfer limits, and soak procedures control thermal gradients. Low-temperature grips and extensometry are mandatory; liquid-nitrogen supply and safety interlocks apply for cryogenic tests.
Compatible equipment
ISO 6892-3 addresses tensile qualification when materials must perform in LNG tanks, aerospace structures, polar infrastructure, or other sub-zero duty. It complements ISO 6892-1 at room temperature and ISO 6892-2 at high temperature within the same ISO 6892 family.
Homogeneous cooling and stable gauge-section temperature are as important as load control. Vector environmental chambers on universal testing machines support controlled cold ramps, LN₂ circuits where required, and extensometer options that maintain traceability through the transition region.
Laboratories typically pair the UTM with a thermal enclosure, cryogenic feed system, and low-temperature grips. Results feed ductile-to-brittle transition studies and acceptance criteria tied to project minimum service temperatures.